Modern Animal: Little Penguin
Future Animal: Bald Penguin
Although not a direct relative of the Little Penguin, the Icadyptes salasi (Latin name Icadyptes salasi) is a very well documented ancestor of the penguins. It roamed the South American continent around 36 million years ago, during the Eocene Epoch. Discovered in Peru in 2007, Icadyptes refers to the Department of Ica, the Peruvian state where its fossil was found, and salasi was named for Rodolfo Salas, a renowned Peruvian palaeontologist. The Icadyptes salasi is the only ancient penguin in which a complete skull has been recovered, and is the third largest penguin in the history of the earth.
Extinction Pressure
One extinction pressure the Icadyptes salasi was under was the rise of the Squalodon- a possible distant ancestor of both the modern-day blue whale and common bottlenose dolphin- as well as other toothed whales. The Icadyptes salasi and these toothed whales had similar diets of fish, and so the Icadyptes salasi had more and more competition for food. Eventually, the Squalodon proved superior at catching prey, and as the population of toothed whales grew, the toothed whales ate more and more fish, and the prey available to the Icadyptes salasi became scarcer and scarcer. The Icadyptes salasi became extinct because it could no longer find enough food to keep the species alive.
Unlike most modern penguins, the Icadyptes salasi did not inhabit the cold desert of Antarctica. Instead, it inhabited the tropical rainforests of South America. A tropical rainforest is an area in the tropics covered in dense vegetation, which receives a lot of rain. The treetops in a rainforest form a high 'roof' called a canopy. There are so many trees that the canopy actually blocks most of the sunlight from entering and reaching the forest floor. This means that vegetation at ground level is not particularly dense, and is generally restricted to herbs, ferns and shrubs which have adapted to survive in the shade, and vines which climb up trees so their upper leaves can receive some sunlight from the canopy. The result of this sparse vegetation is that it is quite easy to walk through a rainforest at ground level. The Icadyptes salasi would not have had difficulty travelling through its habitat.
The Icadyptes salasi lived around 36 million years ago, during the Eocene Epoch. Eocene was a period of high temperatures and rapid global warming. This, combined with the fact that tropical rainforests today remain one of the hottest and most humid biomes, means that the Icadyptes salasi had to live in very high temperatures and very high humidity. Minimum annual rainfall in a rainforest today is 1,750mm, and rainforest temperatures today are never below 18 degrees Celsius. Considering that the Icadyptes salasi lived during the Eocene Epoch, it was probably hotter during the Icadyptes salasi's lifetime than it is today. Also, the rainforest covered a larger area of South America during the Eocene Epoch than it does today.
Rainforests are always teeming with life. Many species of bird, such as toucans and macaws, inhabit the canopy today, and there is little doubt that the ancestors of these birds occupied the canopy when the Icadyptes salasi roamed the undergrowth. The boa constrictor, or an ancestor of the boa constrictor, is one animal the Icadyptes salasi would have encountered, as the boa constrictor also inhabits the forest floor of South American rainforests. The forest floor is also home to jaguars and the black caiman.
Like the modern penguins of today, Icadyptes salasi probably spent most its time in the sea. However, the seas Icadyptes salasi swam in were filled with warmer, tropical currents. This means that the sea animals the Icadyptes salasi would have encountered must have been quite different from the animals modern penguins encounter in colder seas.
In short, the Icadyptes salasi lived in a much hotter and more humid environment than the modern penguin today, and a result of this was in contact with a wider variety of other living creatures.
Structural Adaptations
Long Beak The most obvious structural adaptation of the Icadyptes salasi was its long beak. At around 25 cm, this was significantly longer than the beaks of all modern penguins, even when considering the proportional differences between the Icadyptes salasi and modern penguins in height. The beak consisted of around two thirds of the skull. It is thought that the Icadyptes salasi used its long beak for hunting fish, and that it hunted by spearing the fish on the end of its beak as opposed to capturing its prey between its jaws. This was a useful adaptation as the length of the beak certainly gave the Icadyptes salasi a long reach, and therefore a more competitive edge, thus helping it to easier find food and thus survive. The agility of the fish was an environmental pressure which contributed to the development of a long beak. Upon seeing the Icadyptes salasi arriving, the fish would naturally swim away from the penguin. However, the extra reach afforded by the long beak of the Icadyptes salasi was hopefully enough to allow the penguin to spear the fish before it was able to escape, and therefore catch and eat more food. A shorter beak may have resulted in the Icadyptes salasi not being able to catch the fish.
Large Size Another structural adaptation of the Icadyptes salasi was its large size. Standing at 150 cm, heads above the penguins of today, the Icadyptes salasi certainly was a giant. This would have helped it survive in its rainforest environment, where it would have been surrounded by large creatures such as jaguars, boa constrictors, and anacondas. Had the Icadyptes salasi been smaller, it would have stood no chance of surviving in the rainforest. A smaller size, combined with the fact that all penguins are not very agile on land, meant it would have been regarded by the larger animals as easy targets. Its larger size, however, would have conveyed a sense of assertiveness, and thus discouraged other animals from attacking it. Not being attacked would lead to less injuries and/or fatalities, and therefore help ensure the survival of the species, as more individual Icadyptes salasis would survive. Also, if attacked, its large size would have helped the Icadyptes salasi to fend off predators and given it a fighting chance, whereas a penguin of a smaller size would have been simply crushed. The denser living conditions of a rainforest was an environmental pressure which gave rise to the Icadyptes salasi's larger size, as it had to be large to prevent itself from being attacked by the larger animals surrounding it.
Behavioural Adaptations
Holding its Breath
Because of the Icadyptes salasi's lack of gills, it can be assumed that the Icadyptes salasi, like modern penguins, was unable to breathe underwater. However, because of its large size, the Icadyptes salasi was also unable to porpoise (jump out of, and back into, the water to breathe, much like dolphins or indeed porpoises do) like smaller species of penguins are able to today. It can be assumed that instead, the Icadyptes salasi simply held its breath while diving, remembering to return to the surface periodically to breathe. This behaviour is still exhibited in larger penguin species, such as the emperor penguin, today. In fact, the Emperor Penguin is able to hold its breath for up to 22 minutes, and it can be assumed that the Icadyptes salasi was also able to hold its breath for significant amounts of time. The act of holding its breath aided the Icadyptes salasi in survival because it ensured that it did not drown. As drowning does result in death, the survival rates of the Icadyptes salasi would have been greatly affected had they not held their breath while underwater. The act of holding its breath also helped the Icadyptes salasi survive because, in ensuring that the Icadyptes salasi would not drown, it allowed the Icadyptes salasi to venture underwater and thus hunt and find food. An environmental pressure which led to this adaptation was the fact that the fish, the Icadyptes salasi's main prey, does tend to reside underwater, and therefore, as the Icadyptes salasi lacked gills, the Icadyptes salasi had to find a way to travel underwater without drowning.
Taking Turns to Look After the Egg
It can also be assumed that the male and female Icadyptes salasi partners, like the modern-day emperor penguin, took turns to look after their egg, and later the chick, while the other was off hunting. This would have been a very useful adaptation for the penguins, as the rainforest environment would have seen no lack of predators willing to attack a vulnerable egg. The adult penguin watching over the egg would have deterred predators, and, in the situation that a predator would be daring enough to try and capture the egg in the presence of the parent penguin, the adult would be present to fight off the predator and protect the egg. Hopefully, this ensured that the egg would survive to continue the species. An added benefit of this adaptation was that the parent penguin not watching the egg would be free to hunt, and, knowing that their partner was keeping the egg safe, could swim further from shore. This would have brought the Icadyptes salasi in contact with more fish, and thus, the penguin could catch more prey. This would have been especially useful once the egg has hatched, as the hunting parent would have had to be able to catch enough food to feed both itself and its chick. An environmental pressure which led to this adaptation was the dense living conditions of the rainforest environment. It would not have been safe to leave an egg alone because of the sheer number of potential predators looking for a meal, and so the Icadyptes Salasi adapted so that the egg would never be unwatched.
Physiological Adaptation
Heart Rate
As the Icadyptes salasi and modern day emperor penguin are similar in both size and hunting habits, it can be assumed that certain physiological adaptations of the emperor penguin relating to size and hunting habits can be applied to the Icadyptes salasi. In most penguins, the normal resting heartbeat is 60-70 beats per minute (bpm). However, just before a dive, the penguin's heart rate increases to 180-200 bmp. This allows oxygen to circulate around the body faster, so the penguin can effectively 'store up' on oxygen. Once the penguin dives into the water, the heart rate immediately slows to 100 bpm, and actually slows further to as low as 20 bpm for much of the dive. This means the oxygen stored in the blood is circulated slowly and used as effectively as possible during the dive. As soon as the penguin surfaces, the heart rate again increases to around 200 bpm, to ensure the penguin is supplied with enough oxygen after depriving itself from air during the dive. As both the Icadyptes salasi and the emperor penguin hunt in the sea and are too large to porpoise, it can be assumed that the Icadyptes salasi shares this certain physiological adaptation with the emperor penguin. This interesting heart rate would have been very useful to the Icadyptes salasi, as it would have allowed the penguin to use oxygen in the most effective way possible. The 'storing up' of oxygen by the fast heart beat prior to the dive allowed it to dive further, deeper, and for a longer period of time. In turn, this increased the Icadyptes salasi's chances of catching prey, and thus its chances of survival. An environmental pressure which could have given rise to this adaptation is the fact that the fish tended to inhabit deeper parts of the ocean, giving way to the need of the Icadyptes salasi to dive deeper and for longer. Also, a situation in which the Icadyptes salasi was required to chase fish for an extended period of time in one stretch may have frequently occurred, thus causing the Icadyptes salasi to adapt so that it would eventually be able to catch the fish it was chasing.
Future Animal: Bald Penguin
Although not a direct relative of the Little Penguin, the Icadyptes salasi (Latin name Icadyptes salasi) is a very well documented ancestor of the penguins. It roamed the South American continent around 36 million years ago, during the Eocene Epoch. Discovered in Peru in 2007, Icadyptes refers to the Department of Ica, the Peruvian state where its fossil was found, and salasi was named for Rodolfo Salas, a renowned Peruvian palaeontologist. The Icadyptes salasi is the only ancient penguin in which a complete skull has been recovered, and is the third largest penguin in the history of the earth.
Extinction Pressure
One extinction pressure the Icadyptes salasi was under was the rise of the Squalodon- a possible distant ancestor of both the modern-day blue whale and common bottlenose dolphin- as well as other toothed whales. The Icadyptes salasi and these toothed whales had similar diets of fish, and so the Icadyptes salasi had more and more competition for food. Eventually, the Squalodon proved superior at catching prey, and as the population of toothed whales grew, the toothed whales ate more and more fish, and the prey available to the Icadyptes salasi became scarcer and scarcer. The Icadyptes salasi became extinct because it could no longer find enough food to keep the species alive.
Taxonomy
Kingdom- Animalia
Phylum- Chordata
Class- Aves
Order- Sphenisciformes
Family- Spheniscidae
Genus- Icadyptes
Species- Salasi
Diagram
Habitat
The Icadyptes salasi lived around 36 million years ago, during the Eocene Epoch. Eocene was a period of high temperatures and rapid global warming. This, combined with the fact th
Rainforests are always teeming with life. Many species of bird, such as toucans and macaws, inhabit the canopy today, and there is little doubt that the ancestors of these birds occupied the canopy when the Icadyptes salasi roamed the undergrowth. The boa constrictor, or an ancestor of the boa constrictor, is one animal the Icadyptes salasi would have encountered, as the boa constrictor also inhabits the forest floor of South American rainforests. The forest floor is also home to jaguars and the black caiman.
Like the modern penguins of today, Icadyptes salasi probably spent most its time in the sea. However, the seas Icadyptes salasi swam in were filled with warmer, tropical currents. This means that the sea animals the Icadyptes salasi would have encountered must have been quite different from the animals modern penguins encounter in colder seas.
In short, the Icadyptes salasi lived in a much hotter and more humid environment than the modern penguin today, and a result of this was in contact with a wider variety of other living creatures.
Structural Adaptations
Long Beak
Large Size
Behavioural Adaptations
Holding its Breath
Because of the Icadyptes salasi's lack of gills, it can be assumed that the Icadyptes salasi, like modern penguins, was unable to breathe underwater. However, because of its large size, the Icadyptes salasi was also unable to porpoise (jump out of, and back into, the water to breathe, much like dolphins or indeed porpoises do) like smaller species of penguins are able to today. It can be assumed that instead, the Icadyptes salasi simply held its breath while diving, remembering to return to the surface periodically to breathe. This behaviour is still exhibited in larger penguin species, such as the emperor penguin, today. In fact, the Emperor Penguin is able to hold its breath for up to 22 minutes, and it can be assumed that the Icadyptes salasi was also able to hold its breath for significant amounts of time. The act of holding its breath aided the Icadyptes salasi in survival because it ensured that it did not drown. As drowning does result in death, the survival rates of the Icadyptes salasi would have been greatly affected had they not held their breath while underwater. The act of holding its breath also helped the Icadyptes salasi survive because, in ensuring that the Icadyptes salasi would not drown, it allowed the Icadyptes salasi to venture underwater and thus hunt and find food. An environmental pressure which led to this adaptation was the fact that the fish, the Icadyptes salasi's main prey, does tend to reside underwater, and therefore, as the Icadyptes salasi lacked gills, the Icadyptes salasi had to find a way to travel underwater without drowning.
Taking Turns to Look After the Egg
It can also be assumed that the male and female Icadyptes salasi partners, like the modern-day emperor penguin, took turns to look after their egg, and later the chick, while the other was off hunting. This would have been a very useful adaptation for the penguins, as the rainforest environment would have seen no lack of predators willing to attack a vulnerable egg. The adult penguin watching over the egg would have deterred predators, and, in the situation that a predator would be daring enough to try and capture the egg in the presence of the parent penguin, the adult would be present to fight off the predator and protect the egg. Hopefully, this ensured that the egg would survive to continue the species. An added benefit of this adaptation was that the parent penguin not watching the egg would be free to hunt, and, knowing that their partner was keeping the egg safe, could swim further from shore. This would have brought the Icadyptes salasi in contact with more fish, and thus, the penguin could catch more prey. This would have been especially useful once the egg has hatched, as the hunting parent would have had to be able to catch enough food to feed both itself and its chick. An environmental pressure which led to this adaptation was the dense living conditions of the rainforest environment. It would not have been safe to leave an egg alone because of the sheer number of potential predators looking for a meal, and so the Icadyptes Salasi adapted so that the egg would never be unwatched.
Physiological Adaptation
Heart Rate
As the Icadyptes salasi and modern day emperor penguin are similar in both size and hunting habits, it can be assumed that certain physiological adaptations of the emperor penguin relating to size and hunting habits can be applied to the Icadyptes salasi. In most penguins, the normal resting heartbeat is 60-70 beats per minute (bpm). However, just before a dive, the penguin's heart rate increases to 180-200 bmp. This allows oxygen to circulate around the body faster, so the penguin can effectively 'store up' on oxygen. Once the penguin dives into the water, the heart rate immediately slows to 100 bpm, and actually slows further to as low as 20 bpm for much of the dive. This means the oxygen stored in the blood is circulated slowly and used as effectively as possible during the dive. As soon as the penguin surfaces, the heart rate again increases to around 200 bpm, to ensure the penguin is supplied with enough oxygen after depriving itself from air during the dive. As both the Icadyptes salasi and the emperor penguin hunt in the sea and are too large to porpoise, it can be assumed that the Icadyptes salasi shares this certain physiological adaptation with the emperor penguin. This interesting heart rate would have been very useful to the Icadyptes salasi, as it would have allowed the penguin to use oxygen in the most effective way possible. The 'storing up' of oxygen by the fast heart beat prior to the dive allowed it to dive further, deeper, and for a longer period of time. In turn, this increased the Icadyptes salasi's chances of catching prey, and thus its chances of survival. An environmental pressure which could have given rise to this adaptation is the fact that the fish tended to inhabit deeper parts of the ocean, giving way to the need of the Icadyptes salasi to dive deeper and for longer. Also, a situation in which the Icadyptes salasi was required to chase fish for an extended period of time in one stretch may have frequently occurred, thus causing the Icadyptes salasi to adapt so that it would eventually be able to catch the fish it was chasing.
Bibliography
Ksepka, D. (2009). Icadyptes Salasi- the giant spear-billed penguin. Retrieved 28 June 2010, from http://fossilpenguins.wordpress.com/2009/10/03/8/
Strauss, B. (2010). Icadyptes Giant Penguin. Retrieved 28 June 2010, from http://dinosaurs.about.com/od/prehistoricbirds/p/giant-penguin.htm
Ward, P. (2001). Emperor Penguins Aptenodytes forsteri. Retrieved 29 June 2010, from http://www.coolantarctica.com/Antarctica%20fact%20file/wildlife/Penguin_royalty_King_and_Emperor_penguins.htm
Wikipedia. (2010). Eocene. Retrieved 12 June 2010, from http://en.wikipedia.org/wiki/Eocene
Wikipedia. (2010). Tropical Rainforest. Retrieved 28 June 2010, from http://en.wikipedia.org/wiki/Tropical_rainforest
Wikipedia. (2010). Penguin. Retrieved 28 June 2010, from http://en.wikipedia.org/wiki/Penguins#Palaeeudyptines